JP6741874B2 - Conjugated diene copolymer composition, method for producing the same, and rubber composition containing the same - Google Patents

Description

This application claims the benefit of priority based on Korean Patent Application No. 10-2017-0174776 dated December 19, 2017, and all contents disclosed in the document of the relevant Korean patent application are described in this specification. Incorporated as part of the.

TECHNICAL FIELD The present invention relates to a conjugated diene-based copolymer composition, and more particularly to a conjugated diene-based copolymer composition, a method for producing the same, and a rubber composition containing the same.

In recent years, there has been an increasing interest in environmentally friendly technologies, and as a result, interest in tires applied to automobiles has also been rapidly increasing. The eco-friendly tire is directly connected to fuel efficiency reduction by reducing fuel consumption of an automobile, reduces rolling resistance of the tire to reduce wasteful combustion consumption, and is a main cause of global warming. Is to reduce the emission of.

Therefore, as a rubber material used for such an eco-friendly tire, a conjugated diene polymer having low rolling resistance, excellent wear resistance, and excellent tensile properties, and also having adjustment stability typified by wet grip is required. Has been.

As a method for reducing the rolling resistance of the tire, there is a method for reducing the hysteresis loss of the vulcanized rubber, and as an evaluation index for such a vulcanized rubber, the impact resilience at 50° C. to 80° C., tan δ, and Good. Rich heat generation is used. That is, a rubber material having a large impact resilience at the above temperature or a small tan δ and Goodrich heat generation is preferable.

Natural rubber, polyisoprene rubber, polybutadiene rubber and the like are known as rubber materials having a small hysteresis loss, but these have a problem that they have a small wet grip property. Therefore, in recent years, a conjugated diene-based polymer or copolymer such as styrene-butadiene rubber (hereinafter referred to as SBR) or butadiene rubber (hereinafter referred to as BR) is produced by emulsion polymerization or solution polymerization and used as a tire rubber. ing.

Such a rubber for tires is usually used by being mixed with a filler such as carbon black or silica for complementing the physical properties of the rubber. Among them, SBR produced by solution polymerization is used by introducing a monomer having a polar group at the terminal of the polymer by anionic polymerization to improve the silica affinity of the silica filler. However, there is a problem that abrasion resistance is lower than that of SBR produced by emulsion polymerization. In addition, since SBR produced by emulsion polymerization has difficulty in introducing a repeating unit derived from a desired monomer into a specific portion due to the property of emulsion polymerization, silica as a silica filler in a polymer chain. There is a problem that it is difficult to introduce a polar group for improving the affinity.

Therefore, in order to improve the abrasion resistance of tires, there is a continuing need for research on rubber materials for tires having excellent affinity with fillers, even though SBR produced by emulsion polymerization is used. ..

The problem to be solved by the present invention is to polymerize a conjugated diene-based copolymer by emulsion polymerization in order to solve the problem described in the background art of the above invention, and thereby to improve the abrasion resistance of the rubber composition. It is to impart silica affinity to the conjugated diene-based copolymer while improving the wear resistance of the rubber composition and improve the processability and viscoelasticity of the rubber composition.

That is, the present invention has been made in order to solve the problems of the technology as the background of the invention described above, and imparts silica affinity with the first conjugated diene-based copolymer produced by emulsion polymerization. Then, the rubber composition containing the conjugated diene-based copolymer composition is secured in abrasion resistance and the processability is improved, and the conjugated diene-based copolymer composition is obtained from the second conjugated diene-based copolymer. An object of the present invention is to provide a conjugated diene-based copolymer composition for improving the viscoelastic properties of a rubber composition containing the same, a method for producing the same, and a rubber composition containing the same.

According to one embodiment of the present invention to solve the above problems, the present invention provides a repeating unit of 20% by weight to 60% by weight derived from an aromatic vinyl monomer, derived from a first conjugated diene monomer. The composition contains 35 wt% to 75 wt% of repeating units and 1 wt% to 10 wt% of repeating units derived from a hydroxyalkyl (meth)acrylate monomer, and has a Mooney viscosity (MV) of 30 to 120 at 100°C. And a repeating unit derived from the α-methylstyrene monomer of 20% to 60% by weight, and a repeating unit derived from the second conjugated diene monomer of 40% by weight to Provided is a conjugated diene-based copolymer composition containing 80 wt% and a second conjugated diene-based copolymer having a Mooney viscosity (MV) at 100° C. of more than 120 to 200 or less.

Further, the present invention relates to an aromatic vinyl monomer of 20% by weight to 60% by weight, a first conjugated diene monomer of 35% by weight to 75% by weight, and a hydroxyalkyl(meth)acrylate monomer of 1% by weight. Emulsion-polymerizing a first monomer mixture containing 10 to 10 wt% to produce a first conjugated diene-based copolymer having a Mooney viscosity (MV) of 30 to 120 at 100°C ( S10) and an emulsion polymerization of a second monomer mixture containing 20% to 60% by weight of α-methylstyrene monomer and 40% to 80% by weight of the second conjugated diene monomer, A step (S20) of producing a second conjugated diene-based copolymer having a Mooney viscosity (MV) at 100° C. of more than 120 to 200 or less, and the first step of the step (S10). Provided is a method for producing a conjugated diene-based copolymer composition, which comprises a step (S30) of mixing the conjugated diene-based copolymer and the second conjugated diene-based copolymer produced in the step (S20). ..

The present invention also provides a rubber composition containing a raw material rubber containing the conjugated diene-based copolymer composition.

When the conjugated diene-based copolymer composition according to the present invention is used as a raw rubber component of a rubber composition, it is polymerized by emulsion polymerization to ensure abrasion resistance of the rubber composition containing the conjugated diene-based copolymer. In addition, imparting silica affinity to the conjugated diene-based copolymer composition to improve wear resistance of the rubber composition containing the conjugated diene-based copolymer composition, and to improve processability and viscoelastic properties. It has the effect of being excellent.

The terms and words used in the description and claims of the present invention shall not be construed as being limited to their ordinary or dictionary meanings, and the inventors shall describe their invention in the best possible way. In order to do so, the concept of the term should be interpreted with a meaning and concept consistent with the technical idea of the present invention, based on the principle that the concept can be properly defined.

Hereinafter, the present invention will be described in more detail so that the present invention can be easily understood.

The conjugated diene-based copolymer composition according to the present invention comprises an aromatic vinyl monomer-derived repeating unit of 20% by weight to 60% by weight and a first conjugated diene-based monomer-derived repeating unit of 35% by weight to 75% by weight. %, and a 1% to 10% by weight of a repeating unit derived from a hydroxyalkyl (meth)acrylate monomer, and a Mooney viscosity (MV) at 100° C. of a first conjugated diene system of 30 to 120. 100% by weight containing a copolymer, a repeating unit derived from an α-methylstyrene monomer of 20% by weight to 60% by weight, and a repeating unit derived from a second conjugated diene monomer of 40% by weight to 80% by weight. And a second conjugated diene-based copolymer having a Mooney viscosity (MV) of more than 120 to 200 or less.

In the present invention, the term “repeating unit derived from” may refer to a component, a structure derived from a substance, or the substance itself. As a specific example, the component is introduced at the time of polymerizing a polymer. It may mean a repeating unit in which a monomer participates in a polymerization reaction and is formed in the polymer.

According to an embodiment of the present invention, the conjugated diene-based copolymer composition includes a first conjugated diene-based copolymer and a second conjugated diene-based copolymer formed from different monomers. By including at the same time, when the conjugated diene-based copolymer composition is included as a raw material rubber component of the rubber composition, the first conjugated diene-based copolymer allows the silica affinity with the silica-based filler used as the filler. And the workability are improved, and viscoelastic characteristics are secured by the second conjugated diene-based copolymer.

According to an embodiment of the present invention, the first conjugated diene-based copolymer ensures silica compatibility with a silica-based filler used as a filler in the conjugated diene-based copolymer composition. , 20 wt% to 60 wt% of a repeating unit derived from an aromatic vinyl monomer, 35 wt% to 75 wt% of a repeating unit derived from a first conjugated diene-based monomer, and hydroxy for improving processability. It may contain 1% by weight to 10% by weight of a repeating unit derived from an alkyl(meth)acrylate monomer.

According to one embodiment of the present invention, the repeating unit derived from the aromatic vinyl monomer of the first conjugated diene-based copolymer is a repeating unit formed by polymerization of the aromatic vinyl monomer during the polymerization. May form a main chain (back bone) in the copolymer together with the repeating unit derived from the first conjugated diene monomer and the repeating unit derived from the hydroxyalkyl (meth)acrylate monomer. The aromatic vinyl monomer for forming the repeating unit derived from the aromatic vinyl monomer may be an aromatic vinyl monomer other than α-methylstyrene contained in the second conjugated diene-based copolymer. It may be a vinyl monomer, and specific examples thereof include styrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene, 4-cyclohexylstyrene, 4-(p-methylphenyl). ) One or more kinds selected from the group consisting of styrene and 1-vinyl-5-hexylnaphthalene may be used, and more specific example may be styrene.

According to an exemplary embodiment of the present invention, the content of the repeating unit derived from the aromatic vinyl monomer may be 20 wt% to 60 wt% or 30 wt% based on the total content of the first conjugated diene-based copolymer. It may be 50% by weight to 50% by weight, or 35% by weight to 45% by weight. Within this range, the processability of the conjugated diene-based copolymer composition is improved, and the conjugated diene-based copolymer is improved. It has an effect of preventing deterioration of mechanical properties of a rubber composition containing the composition as a raw rubber component.

In addition, according to one embodiment of the present invention, the repeating unit derived from the first conjugated diene-based monomer of the first conjugated diene-based copolymer is a polymer of the first conjugated diene-based monomer during polymerization. May form a main chain in the copolymer together with the repeating unit derived from the aromatic vinyl monomer and the repeating unit derived from the hydroxyalkyl (meth)acrylate monomer. The first conjugated diene-based monomer for forming the repeating unit derived from the first conjugated diene-based monomer may be 1,3-butadiene or 2,3-dimethyl-1. ,3-Butadiene, piperylene, 3-butyl-1,3-octadiene, isoprene, 2-phenyl-1,3-butadiene and 2-halo-1,3-butadiene (halo means a halogen atom). It may be one or more selected from the group consisting of, and a specific example may be 1,3-butadiene.

According to an embodiment of the present invention, the content of the repeating unit derived from the first conjugated diene-based monomer is 35 wt% to 75 wt% based on the total content of the first conjugated diene-based copolymer. %, 40% by weight to 70% by weight, or 50% by weight to 60% by weight. Within this range, the viscosity of the rubber composition containing the conjugated diene copolymer composition as a raw rubber component is It has the effect of being excellent in elastic properties and being excellent in balance between physical properties.

In addition, according to an embodiment of the present invention, the repeating unit derived from the hydroxyalkyl (meth)acrylate monomer of the first conjugated diene-based copolymer is formed by polymerizing the hydroxyalkyl (meth)acrylate monomer during polymerization. May form a main chain in the copolymer together with the repeating unit derived from the aromatic vinyl monomer and the repeating unit derived from the first conjugated diene monomer. Which may be a repeating unit distributed in the copolymer to impart an affinity with the silica-based filler. The hydroxy groups of the repeating units derived from the distributed hydroxyalkyl (meth)acrylate monomer are hydrogen-bonded to the hydroxy groups present in the silica-based filler, and the conjugated diene-based copolymer composition and the silica-based filler are thus obtained. It has the effect of imparting an affinity with and having excellent dispersibility of the filler in the rubber composition to improve the mechanical properties of the rubber composition.

According to an embodiment of the present invention, the hydroxyalkyl (meth)acrylate monomer has an alkyl group having 1 to 10 carbon atoms, 2 to 8 carbon atoms, or 2 to 4 carbon atoms. It may be an alkyl (meth)acrylate monomer, and when it is within this range, it is possible to prevent the increase of hydrophobicity of the hydroxyalkyl (meth)acrylate monomer due to the alkyl group, thereby forming a silica-based filler. It has an effect of improving affinity. As a specific example, the hydroxyalkyl (meth)acrylate monomer is one or more selected from the group consisting of hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate and hydroxybutyl (meth)acrylate. May be. Here, the hydroxyalkyl (meth)acrylate monomer may mean hydroxyalkyl acrylate or hydroxyalkyl methacrylate.

Also, according to one embodiment of the present invention, the content of the repeating unit derived from the hydroxyalkyl (meth)acrylate monomer is 1 wt% to the total content of the first conjugated diene-based copolymer. 10% by weight, 1% by weight to 7% by weight, or 1% by weight to 5% by weight may be added, and within this range, other monomers in the first conjugated diene-based copolymer may be added. Prevents deterioration of the mechanical properties of the rubber composition due to a decrease in the content of the repeating unit derived from it, and maximizes the affinity with the silica-based filler to improve the mechanical properties of the rubber composition as a whole. The effect is that the balance between physical properties is excellent.

According to an embodiment of the present invention, the first conjugated diene-based copolymer has a Mooney viscosity (MV) at 100° C. of 30 to 120, 50 to 120, or 60 to 90. It may be present, and when it is within this range, there is an effect that the mechanical properties of the conjugated diene-based copolymer composition are prevented from being deteriorated and the processability is improved.

According to an embodiment of the present invention, the first conjugated diene-based copolymer has a weight average molecular weight of 10,000 g/mol to 800,000 g/mol, 100,000 g/mol to 800,000 g/mol. It may be mol, or 300,000 g/mol to 800,000 g/mol, and within this range, the affinity with the silica-based filler is maximized, and the processability of the conjugated diene-based copolymer composition is increased. Has the effect of improving.

In addition, according to an embodiment of the present invention, the second conjugated diene-based copolymer is used in the conjugated diene-based copolymer composition in order to secure viscoelastic properties. It may contain 20% to 60% by weight of the repeating unit derived from the body and 40% to 80% by weight of the repeating unit derived from the second conjugated diene monomer.

According to an embodiment of the present invention, the repeating unit derived from the α-methylstyrene monomer of the second conjugated diene-based copolymer is a repeating unit formed by polymerization of the α-methylstyrene monomer during polymerization. Or may form a main chain in the copolymer together with the repeating unit derived from the second conjugated diene-based monomer. The repeating unit derived from the α-methylstyrene monomer formed by polymerizing the α-methylstyrene monomer is derived from a styrene monomer formed by polymerizing a commonly used styrene monomer. Since the glass transition temperature is higher than that of the repeating unit, it is possible to form a copolymer having a higher glass transition temperature even when added and included in the same amount, and thus, due to such a high glass transition temperature, There is an effect of improving viscoelastic properties such as wet grip properties of a rubber composition containing the conjugated diene-based copolymer composition containing the second conjugated diene-based copolymer as a raw material rubber component. Further, according to the present invention, when the second conjugated diene-based copolymer contains a repeating unit derived from an α-methylstyrene monomer, a styrene monomer having a high reactivity and a high rate of forming a block is obtained. In comparison, during the polymerization of the random copolymer, the random ratio is high and the repeating units derived from the α-methylstyrene monomer are uniformly distributed in the copolymer, and the balance between the physical properties of the rubber composition is excellent. There is an effect.

According to an embodiment of the present invention, the content of the repeating unit derived from the α-methylstyrene monomer is 20 wt% to 60 wt% based on the total content of the second conjugated diene copolymer. It may be 30% by weight to 50% by weight, or 35% by weight to 45% by weight. Within this range, the processability of the rubber composition containing the conjugated diene copolymer composition as a raw rubber component and It is effective in preventing the deterioration of tensile properties and being excellent in viscoelastic properties.

In addition, according to one embodiment of the present invention, the repeating unit derived from the second conjugated diene-based monomer of the second conjugated diene-based copolymer is a polymer of the second conjugated diene-based monomer during the polymerization. And a repeating unit derived from the α-methylstyrene monomer may form a main chain in the copolymer, and the second conjugated diene system may be used. The second conjugated diene-based monomer for forming the repeating unit derived from the monomer is the same as or different from the first conjugated diene-based monomer of the first conjugated diene-based copolymer. As a specific example, 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-1,3-octadiene, isoprene, 2-phenyl-1,3- It may be one or more selected from the group consisting of butadiene and 2-halo-1,3-butadiene (halo means a halogen atom), and more specific examples include 1,3-butadiene. May be

According to an embodiment of the present invention, the content of the repeating unit derived from the first conjugated diene-based monomer is 40 wt% to 80 wt% based on the total content of the first conjugated diene-based copolymer. %, 50% by weight to 70% by weight, or 55% by weight to 65% by weight, and within this range, the viscosity of the rubber composition containing the conjugated diene copolymer composition as a raw rubber component. It has the effect of being excellent in elastic properties and being excellent in balance between physical properties.

According to an embodiment of the present invention, the second conjugated diene-based copolymer has a Mooney viscosity (MV) at 100° C. of more than 120 to less than 200, 150 to 200, or 160 to 200. It may be 180, and within this range, the glass transition temperature of the second conjugated diene-based copolymer is high, which has the effect of excellent viscoelastic properties of the rubber composition.

According to an embodiment of the present invention, the second conjugated diene-based copolymer has a weight average molecular weight of more than 800,000 g/mol to less than 5,000,000 g/mol, more than 800,000 g/mol. ~3,000,000 g/mol or less, or more than 800,000 g/mol to 1,500,000 g/mol or less, and within this range, the glass of the second conjugated diene-based copolymer. The transition temperature is high, which has the effect of excellent viscoelastic properties of the rubber composition.

According to an embodiment of the present invention, the first conjugated diene-based copolymer and the second conjugated diene-based copolymer may each be a random copolymer, and in this case, a balance between physical properties is obtained. It has an excellent effect. The random copolymer may mean that the repeating units derived from each of the monomers forming the copolymer are randomly arranged.

Also, according to an embodiment of the present invention, the content of the first conjugated diene-based copolymer is 10 wt% to 90 wt% and 20 wt% with respect to the total content of the conjugated diene-based copolymer composition. % To 80% by weight, or 40% to 60% by weight, and the content of the second conjugated diene-based copolymer is 10% to 90% by weight, 20% to 80% by weight, Alternatively, it may be 40% by weight to 60% by weight, and within this range, the first conjugated diene-based copolymer for imparting silica affinity and improving processability, and viscoelastic properties Mixing with the second conjugated diene-based copolymer for improvement has the effects of preventing a decrease in the balance between physical properties and maximizing the physical properties described above.

According to an embodiment of the present invention, the conjugated diene-based copolymer composition has a Mooney viscosity (MV) at 100° C. of 20 to 150, 30 to 120, or 45 to 85. If it is within this range, there is an effect that the processability and productivity of the rubber composition are excellent, and the mechanical properties are excellent.

Further, according to one embodiment of the present invention, the conjugated diene-based copolymer composition may have a glass transition temperature of -60°C or higher, -50°C or higher, or -50°C to -15°C. When it is within this range, there is an effect that the rubber composition containing the conjugated diene-based copolymer is excellent in abrasion resistance and viscoelasticity.

The present invention also provides a method for producing the conjugated diene-based copolymer composition for producing the conjugated diene-based copolymer composition. The method for producing the conjugated diene-based copolymer composition comprises: 20% by weight to 60% by weight of an aromatic vinyl monomer; 35% by weight to 75% by weight of a first conjugated diene monomer; ) A first conjugated diene system having a Mooney viscosity (MV) of 30 to 120 at 100° C., which is obtained by emulsion polymerization of a first monomer mixture containing 1 wt% to 10 wt% of an acrylate monomer. A step (S10) of producing a copolymer, and a second monomer containing 20% to 60% by weight of an α-methylstyrene monomer and 40% to 80% by weight of a second conjugated diene monomer. Emulsion polymerization of the monomer mixture to produce a second conjugated diene-based copolymer having a Mooney viscosity (MV) at 100° C. of more than 120 to 200 (S20), and the above (S10). The method may include a step (S30) of mixing the first conjugated diene-based copolymer manufactured in the step and the second conjugated diene-based copolymer manufactured in the step (S20).

According to an embodiment of the present invention, the first conjugated diene-based copolymer produced in the step (S10) and the second conjugated diene-based copolymer produced in the step (S20) are As described above, it may be produced by emulsion polymerization. The emulsion polymerization may be carried out by an emulsion polymerization method for carrying out radical polymerization of each monomer, and as a specific example, it may be carried out in the presence of an emulsifier, an initiator and a molecular weight modifier. ..

According to an embodiment of the present invention, the first monomer mixture introduced in the step (S10) and the second monomer mixture introduced in the step (S20) are the first conjugate. A monomer mixture containing each monomer for forming a repeating unit derived from each monomer contained in the diene-based copolymer and the second conjugated diene-based copolymer may be used. The content of each monomer in the monomer mixture and the second monomer mixture may be the same as the content of the repeating unit derived from each monomer.

In addition, according to an embodiment of the present invention, the emulsion polymerization in the step (S10) and the emulsion polymerization in the step (S20) may be performed independently, and after the step (S10) is performed. , In order, the step (S20) may be performed, or the step (S20) may be performed first and then the step (S10) may be performed.

According to one embodiment of the present invention, as the emulsifier added in the emulsion polymerization in the step (S10) and the step (S20), an emulsifier usually used in the technical field can be used. It is possible to use one or more emulsifiers selected from the group consisting of a phosphate type, a carboxylate type, a sulfate type, a succinate type, a sulfosuccinate type, a sulfonate type and a disulfonate type. As a more specific example, one or more emulsifiers selected from the group consisting of alkyl aryl sulfonates, alkali methyl alkyl sulphates, sulfonated alkyl esters, soaps of fatty acids and alkali salts of rosin acids can be used, In this case, there is an effect of providing a stable polymerization environment. The emulsifier is, for example, 0.1 parts by weight to 5 parts by weight, or 0.5 parts by weight to 100 parts by weight of the total amount of the first monomer mixture and the second monomer mixture. It may be added in an amount of 3 parts by weight. When the amount is within this range, the polymerization stability of the latex is excellent, and there is an effect of minimizing the generation of bubbles during the polymerization.

According to one embodiment of the present invention, the molecular weight modifier added during the emulsion polymerization in the step (S10) and the step (S20) includes α-methylstyrene dimer, t-dodecyl mercaptan, n-dodecyl mercaptan and Mercaptans such as octyl mercaptan; halogenated hydrocarbons such as carbon tetrachloride, methylene chloride and methylene bromide; selected from the group consisting of sulfur-containing compounds such as tetraethylthiuram disulfide, dipentamethylene thiuram disulfide and diisopropylxanthogen disulfide 1 More than one species may be used, and a specific example may be t-dodecyl mercaptan. For example, the molecular weight modifier may be added in an amount of 0.2 parts by weight to 0.6 parts by weight based on 100 parts by weight of the total amount of the first monomer mixture and the second monomer mixture. Good.

According to one embodiment of the present invention, the polymerization initiator added during the emulsion polymerization of the step (S10) and the step (S20) may have the same molecular weight, gel content and gel structure of the conjugated diene-based copolymer of the present invention. It is for adjusting and may be a radical initiator. Examples of the radical initiator include inorganic peroxides such as sodium persulfate, potassium persulfate, ammonium persulfate, potassium perphosphate, and hydrogen peroxide; t-butyl peroxide, cumene hydroperoxide, p-menthane hydro. Peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide, acetyl peroxide, isobutyl peroxide, octanoyl peroxide, dibenzoyl peroxide, 3,5,5-trimethylhexanol peroxide, and t- Organic peroxides such as butyl peroxyisobutyrate; from azobis compounds such as azobisisobutyronitrile, azobis-2,4-dimethylvaleronitrile, azobiscyclohexanecarbonitrile, and methyl azobisisobutyrate (butyrate) It may be one or more selected from the group consisting of As a specific example, the radical initiator may be an inorganic peroxide, and as a more specific example, a persulfate salt. The polymerization initiator is, for example, 0.01 to 2 parts by weight, or 0.02 to 1% with respect to the total content of 100 parts by weight of each of the first monomer mixture and the second monomer mixture. 5 parts by weight may be added, and when it is within this range, the polymerization rate can be appropriately adjusted, so that the polymerization can be controlled and the productivity is excellent.

Further, according to one embodiment of the present invention, during the emulsion polymerization of the step (S10) and the step (S20), an activator and a chelating agent may be added, if necessary, within a range not deteriorating the physical properties of the rubber composition. Additives such as a dispersant, a pH adjustor, a deoxidizer, a particle size adjuster, an antioxidant, and an oxygen scavenger may be added.

According to one embodiment of the present invention, the method for producing the conjugated diene-based copolymer composition comprises: a first conjugated diene-based copolymer latex and a second conjugated diene-based copolymer latex obtained by emulsion polymerization. , Or a step of aggregating, aging, dehydrating and drying in order to obtain the mixed latex thereof in the form of powder.

Meanwhile, according to an embodiment of the present invention, the step (S30) includes the first conjugated diene-based copolymer prepared in the step (S10) and the second conjugated diene copolymer prepared in the step (S20). A step of mixing with the conjugated diene-based copolymer, wherein the conjugated diene-based copolymers prepared in the step (S10) and the step (S20) are mixed in a powder form. The first conjugated diene-based copolymer latex including the first conjugated diene-based copolymer prepared in the step (S10) and the step (S20) may be performed for uniform mixing. The second conjugated diene-based copolymer latex containing the second conjugated diene-based copolymer produced in (1) may be mixed in the form of a latex.

Further, according to the present invention, there is provided a rubber composition containing a raw material rubber containing the conjugated diene-based copolymer composition. According to an embodiment of the present invention, the raw rubber may include the conjugated diene-based copolymer composition in an amount of 10 wt% or more, 10 wt% to 100 wt%, or 50 wt% to 90 wt%. Well, when it is within this range, there is an effect that mechanical properties such as tensile strength and abrasion resistance are excellent, and a balance between the respective physical properties is excellent.

Further, according to one embodiment of the present invention, the raw material rubber is, in addition to the conjugated diene-based copolymer, optionally one or more rubber components selected from the group consisting of natural rubber and synthetic rubber. May be further included. At this time, the rubber component may be included in an amount of 90% by weight or less, or 10% by weight to 40% by weight, based on the total content of the raw material rubber. As a specific example, the rubber component may be included in an amount of 1 to 900 parts by weight based on 100 parts by weight of the conjugated diene-based copolymer. The rubber component may be, for example, natural rubber or synthetic rubber, and as a specific example, natural rubber (NR) containing cis-1,4-polyisoprene; modified or purified from the general natural rubber. Modified natural rubber such as epoxidized natural rubber (ENR), deproteinized natural rubber (DPNR), hydrogenated natural rubber; styrene-butadiene copolymer (SBR), polybutadiene (BR), polyisoprene (IR), butyl rubber (IIR), ethylene-propylene copolymer, polyisobutylene-co-isoprene, neoprene, poly(ethylene-co-propylene), poly(styrene-co-butadiene), poly(styrene-co-isoprene), poly(styrene) -Co-isoprene-co-butadiene), poly(isoprene-co-butadiene), poly(ethylene-co-propylene-co-diene), polysulfide rubber, acrylic rubber, urethane rubber, silicone rubber, epichlorohydrin rubber, butyl rubber Synthetic rubber such as halogenated butyl rubber may be used, and any one of them or a mixture of two or more thereof may be used.

According to an embodiment of the present invention, the rubber composition may include 1 to 200 parts by weight, or 10 to 120 parts by weight of a silica-based filler based on 100 parts by weight of the raw rubber. As a specific example, the silica-based filler may be one or more selected from the group consisting of wet silica, dry silica, calcium silicate, aluminum silicate, and colloidal silica, and preferably has fracture properties. The wet silica may have the highest effect of improving the above-mentioned effect and the effect of simultaneously achieving the wet grip property. Further, the rubber composition may further contain a carbon black filler, if necessary.

As still another example, when silica is used as the filler, a silane coupling agent for improving the reinforcing property and the low heat buildup property may be used together. Specific examples of the silane coupling agent include bis(3-triethoxysilylpropyl) tetrasulfide, bis(3-triethoxysilylpropyl) trisulfide, bis(3-triethoxysilylpropyl) disulfide, bis( 2-triethoxysilylethyl)tetrasulfide, bis(3-trimethoxysilylpropyl)tetrasulfide, bis(2-trimethoxysilylethyl)tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-trimethoxysilylpropyl-N,N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropyl-N,N-dimethylthiocarbamoyltetrasulfide, 2-triethoxysilylethyl-N,N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropyl benzothiazolyl tetrasulfide, 3-triethoxysilylpropyl benzoyl tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide , 3-trimethoxysilylpropyl methacrylate monosulfide, bis(3-diethoxymethylsilylpropyl) tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N,N-dimethylthiocarbamoyl tetrasulfide, or dimethoxymethyl It may be silylpropylbenzothiazolyl tetrasulfide and the like, and any one of them or a mixture of two or more thereof can be used. Preferably, considering the effect of improving the reinforcing property, bis(3-triethoxysilylpropyl) polysulfide or 3-trimethoxysilylpropylbenzothiazyltetrasulfide may be used.

In addition, the rubber composition according to an embodiment of the present invention includes a first conjugated diene-based copolymer in which a functional group having an affinity for silica is introduced into the conjugated diene-based copolymer composition. Therefore, the compounding amount of the silane coupling agent can be reduced as compared with the usual case, whereby the silane coupling agent is contained in an amount of 1 to 20 parts by weight based on 100 parts by weight of the silica-based filler. It may be used in parts by weight, or 5 to 15 parts by weight. Within this range, the effect as a coupling agent is sufficiently exerted, and the raw rubber is prevented from gelling.

The rubber composition according to one embodiment of the present invention may be sulfur-crosslinkable and may further include a vulcanizing agent. Specifically, the vulcanizing agent may be sulfur powder, and may be included in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the raw rubber. Within this range, the vulcanized rubber composition has the effects of ensuring the required elastic modulus and strength and excellent fuel economy.

The rubber composition according to one embodiment of the present invention is, in addition to the above-mentioned components, various additives usually used in the rubber industry, specifically, vulcanization accelerators, process oils, plasticizers, and anti-aging agents. An agent, an anti-scorch agent, a zinc white, a stearic acid, a thermosetting resin, a thermoplastic resin, or the like may be further included.

Examples of the vulcanization accelerator include thiazole compounds such as M (2-mercaptobenzothiazole), DM (dibenzothiazyl disulfide), and CZ (N-cyclohexyl-2-benzothiazyl sulfenamide), or DPG. Guanidine compounds such as (diphenylguanidine) can be used, and may be contained in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the raw rubber.

The processing oil acts as a softening agent in the rubber composition, and may be, for example, a paraffin-based, naphthene-based, or aromatic compound, and in consideration of tensile strength and abrasion resistance. , Aromatic process oils can be used, and naphthenic or paraffinic process oils can be used in consideration of hysteresis loss and low temperature characteristics. The process oil may be contained, for example, in an amount of 100 parts by weight or less based on 100 parts by weight of the raw rubber, and within this range, the vulcanized rubber has a tensile strength and a low heat buildup (low fuel consumption). The effect is to prevent the decrease of.

Examples of the antioxidant include N-isopropyl-N'-phenyl-p-phenylenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, 6-ethoxy-2,2. , 4-trimethyl-1,2-dihydroquinoline, or a high-temperature condensate of diphenylamine and acetone may be used, and 0.1 to 6 parts by weight may be used with respect to 100 parts by weight of the raw rubber. ..

The rubber composition according to one embodiment of the present invention is obtained by kneading using a kneading machine such as a Banbury mixer, a roll, an internal mixer according to the compounding formulation, and after the molding process, a vulcanization step. As a result, it is possible to obtain a rubber composition having low heat generation and excellent abrasion resistance.

According to one embodiment of the present invention, the rubber composition, tire tread, undertread, sidewall, carcass coating rubber, belt coating rubber, bead filler, chafer, or each member of the tire such as bead coating rubber, It is useful in the production of various industrial rubber products such as dustproof rubber, belt conveyors and hoses.

The present invention provides a tire manufactured using the rubber composition.

The tire may include a tire or a tire tread, and as a specific example, the tire or the tire tread is a tire or a tire tread used for a summer tire, a winter tire, a snow tire, or an all-season (for four seasons) tire. May be

Hereinafter, the present invention will be described in more detail with reference to examples. However, it is obvious to a person skilled in the art that the following examples are merely for exemplifying the present invention, and various changes and modifications can be made within the scope and technical idea of the present invention. However, the scope of the present invention is not limited to these.

Example Example 1
<Production of First Conjugated Diene Copolymer>
In a nitrogen-substituted polymerization reactor (autoclave), 200 parts by weight of ion-exchanged water, 46 parts by weight of styrene as a monomer, 51 parts by weight of 1,3-butadiene, 3 parts by weight of hydroxypropylmethacrylate, fatty acid as an emulsifier 5 parts by weight of an alkali salt of soap and rosin acid, 0.5 part by weight of cumene hydroperoxide as an initiator, and 0.5 part by weight of dodecyl mercaptan as a molecular weight regulator were added all at once and reacted at a reaction temperature of 10°C. It was The reaction was terminated when the polymerization conversion rate was 60% to produce a first conjugated diene-based copolymer latex.

<Production of Second Conjugated Diene Copolymer>
In a nitrogen-substituted polymerization reactor (autoclave), 200 parts by weight of ion-exchanged water, 53 parts by weight of α-methylstyrene, 47 parts by weight of 1,3-butadiene as a monomer, soap of fatty acid and rosin acid as an emulsifier. 5 parts by weight of alkali salt, 0.5 part by weight of cumene hydroperoxide as an initiator, and 0.5 part by weight of dodecyl mercaptan as a molecular weight modifier were added all at once and reacted at a reaction temperature of 10°C. The reaction was terminated when the polymerization conversion rate was 60% to produce a second conjugated diene-based copolymer latex.

<Production of Conjugated Diene Copolymer Composition>
50 parts by weight of the above-mentioned first conjugated diene copolymer latex (based on solid content) and 50 parts by weight of the second conjugated diene copolymer latex (based on solid content) were stirred at room temperature for 1 hour to conjugate A diene copolymer composition latex was obtained. The obtained conjugated diene-based copolymer composition latex was slowly dropped into methanol to cause precipitation, followed by drying in an oven at 100° C. for 1 hour to obtain a conjugated diene-based copolymer composition powder. ..

Example 2
The same procedure as in Example 1 was performed except that 5 parts by weight of hydroxypropyl methacrylate was added instead of 3 parts by weight of hydroxypropyl methacrylate in the production of the first conjugated diene-based copolymer. It was

Example 3
The same procedure as in Example 1 was repeated except that 3 parts by weight of hydroxymethyl methacrylate was added instead of 3 parts by weight of hydroxypropyl methacrylate in the production of the first conjugated diene-based copolymer. It was

Example 4
The same procedure as in Example 1 was repeated except that 3 parts by weight of hydroxybutyl methacrylate was added instead of 3 parts by weight of hydroxypropyl methacrylate in the production of the first conjugated diene-based copolymer. It was

Example 5
In Example 1, 5 parts by weight of hydroxypropyl methacrylate was added instead of 3 parts by weight of hydroxypropyl methacrylate during the production of the first conjugated diene copolymer, and when the conjugated diene copolymer composition was produced, In place of 50 parts by weight of the first conjugated diene copolymer latex and 50 parts by weight of the second conjugated diene copolymer latex, 40 parts by weight of the first conjugated diene copolymer latex and second conjugated diene system The same procedure as in Example 1 was repeated except that 60 parts by weight of the copolymer latex was mixed.

Comparative Example 1
The same procedure as in Example 1 was performed except that the same amount of styrene was added instead of α-methylstyrene during the production of the second conjugated diene-based copolymer.

Comparative example 2
In Example 1, 1 part by weight of dodecyl mercaptan was added during the production of the first conjugated diene-based copolymer, and 0.1 part by weight of dodecyl mercaptan was added during the production of the second conjugated diene-based copolymer. Except for the above, the same method as in Example 1 was performed.

Comparative Example 3
The same procedure as in Example 1 was performed except that 15 parts by weight of hydroxypropyl methacrylate was added instead of 3 parts by weight of hydroxypropyl methacrylate in the production of the first conjugated diene-based copolymer. It was

Comparative Example 4
In Example 1, the same procedure as in Example 1 was performed, except that hydroxypropyl methacrylate was not added during the production of the first conjugated diene-based copolymer.

Experimental example Experimental example 1
The Mooney viscosity (MV) of the first conjugated diene-based copolymer and the second conjugated diene-based copolymer produced in Examples 1 to 5 and Comparative Examples 1 to 4 and the conjugated diene-based copolymer composition. The Mooney viscosity (MV) and glass transition temperature (Tg) of the product are shown in Tables 1 and 2 below. If the Mooney viscosities are different even though they are manufactured by the same method in each of the Examples and Comparative Examples, it is due to experimental error.

* Mooney viscosity (MV, (ML1+4, @100°C) MU): Measured by MV-2000 (manufactured by ALPHA Technologies) at 100°C using Rotor Speed 2 ± 0.02 rpm, and Large Rotorfmf. The sample used at this time was left at room temperature (23±3° C.) for 30 minutes or more, 27±3 g was sampled and filled in the die cavity, and the platen was operated for 4 minutes for measurement. did.

*Glass transition temperature (Tg, °C): measured by an ordinary method using DSC.

Experimental example 2
In order to compare and analyze the physical properties of the rubber composition containing the conjugated diene-based copolymer composition prepared in Examples 1 to 5 and Comparative Examples 1 to 4 and the molded article produced by the composition, the following procedure was performed. A rubber test piece was manufactured and its Mooney viscosity, tensile property, abrasion resistance and viscoelastic property were measured by the following methods, and the results are shown in Tables 4 and 5.

*Manufacture of rubber test piece 100 parts by weight of the conjugated diene-based copolymer composition of Examples 1 to 5 and Comparative Examples 1 to 4 and 30 parts by weight of butadiene rubber (manufactured by LG Chem Limited, grade name BR1208) were added. The raw rubber was compounded under the compounding conditions shown in Table 3 below. The raw materials in Table 3 are each part by weight based on 100 parts by weight of the conjugated diene-based copolymer.

Specifically, the rubber test piece is kneaded through the first stage kneading and the second stage kneading. In the first stage kneading, using a Banbury mixer equipped with a temperature control device, raw material rubber (conjugated diene copolymer composition and butadiene rubber), filler, organic silane coupling agent, process oil, zinc white, stearic acid The antioxidant, antioxidant, and wax were kneaded to obtain a primary blend. In the second-stage kneading, after cooling the primary blend to room temperature, the primary blend, sulfur, a rubber accelerator, and a vulcanization accelerator are added to a kneader and mixed at a temperature of 100° C. or lower to obtain 2 After obtaining the following compound, rubber test pieces for measuring the following physical properties were manufactured.

*Tensile properties: For the tensile properties, each test piece was manufactured according to the tensile test method of ASTM 412, and the tensile strength at the time of cutting the test piece and the tensile stress at 300% elongation (300% modulus) were measured. Specifically, the tensile properties were measured at room temperature at a speed of 50 cm/min using a Universal Test Machine 4204 (manufactured by Instron) tensile tester.

*Abrasion resistance (DIN loss weight): Using the DIN abrasion tester, the abrasion resistance of the produced rubber test piece was measured by applying a load of 10 N to a rotating drum (Drum) to which abrasion paper was attached. After moving the rubber test piece in the direction perpendicular to the rotating direction of the drum, the amount of abrasion was measured. The rotation speed of the drum is 40 rpm, and the total moving distance of the test piece when the test is completed is 40 m.

*Viscoelastic property: using DMTS 500N (manufactured by Gabo, Germany) at a frequency of 10 Hz, Prestrain 5%, and Dynamic Strain 0.5%, while raising the temperature at 2°C/min within a temperature range of -40°C to 70°C. The temperature Sweep was performed to measure tan δ. In the tan δ graph, Compound Tg is shown from the X-axis value of the inflection point. The Payne effect is indicated by the difference between the minimum value and the maximum value at the deformation of 0.28% to 40%. The higher the tan δ at 0°C which is a low temperature, the better the wet grip property, and the lower the tan δ at 60°C which is a high temperature is, the less hysteresis loss and the better running resistance (fuel consumption) is. Means

*Workability: Roll temperature is 50° C., roll interval is 1 mm to 4 mm, evaluation is performed in 0.5 mm units, 400 g of sample is initially milled for 30 seconds, and molding stability during compounding is 0 to 5 points. The workability was evaluated by evaluating the points.

As shown in Tables 4 and 5, it was confirmed that the conjugated diene-based copolymer composition according to the present invention has excellent tensile properties, abrasion resistance, viscoelastic properties, and processability. We were able to.

On the other hand, Comparative Example 1 in which styrene was added to the second conjugated diene-based copolymer instead of α-methylstyrene, the first conjugated diene-based copolymer had a high viscosity, and the second conjugated diene-based copolymer Comparative Example 2 in which a coalesced product was prepared with a bottom viscosity, Comparative Example 3 containing a first conjugated diene-based copolymer containing an excessive amount of repeating units derived from a hydroxyalkyl(meth)acrylate monomer, and hydroxyalkyl(meth)acrylate. It was confirmed that Comparative Example 4 containing the first conjugated diene-based copolymer containing no monomer-derived repeating unit was inferior in tensile property, abrasion resistance, viscoelastic property and processability. We were able to.

From the above results, the present inventors have found that when the conjugated diene-based copolymer composition according to the present invention is used as a raw material rubber component of a rubber composition, the conjugated diene-based copolymer is polymerized by emulsion polymerization. Abrasion resistance of a rubber composition containing a conjugated diene-based copolymer composition by ensuring wear resistance of the rubber composition containing the polymer and imparting silica affinity to the conjugated diene-based copolymer composition It was confirmed that the workability was improved and the workability and viscoelasticity were excellent.

Claims (10)

20% to 60% by weight of repeating unit derived from aromatic vinyl monomer, 35% to 75% by weight of repeating unit derived from first conjugated diene monomer, and derived from hydroxyalkyl (meth)acrylate monomer A first conjugated diene-based copolymer having a Mooney viscosity (MV) of 30 to 120 at 100° C., which comprises 1 wt% to 10 wt% of a repeating unit of
20% by weight to 60% by weight of the repeating unit derived from the α-methylstyrene monomer, and 40% by weight to 80% by weight of the repeating unit derived from the second conjugated diene monomer, and the Mooney viscosity at 100°C ( A conjugated diene-based copolymer composition comprising a second conjugated diene-based copolymer having a Mooney viscosity (MV) of more than 120 to 200 or less. The aromatic vinyl monomer includes styrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 1-vinylnaphthalene, 4-cyclohexylstyrene, 4-(p-methylphenyl)styrene and 1-vinyl-. The conjugated diene-based copolymer composition according to claim 1, which is one or more selected from the group consisting of 5-hexylnaphthalene. The hydroxyalkyl (meth) acrylate monomer is one or more selected hydroxyethyl (meth) acrylate, hydroxy propyl (meth) the group consisting of acrylate and hydroxybutyl (meth) acrylate, according to claim 1 or 2 The conjugated diene-based copolymer composition as described in 1. The conjugated diene-based copolymer according to any one of claims 1 to 3, wherein the first conjugated diene-based copolymer has a Mooney viscosity (MV) at 100°C of 60 to 90. Composition. The conjugated diene-based copolymer according to any one of claims 1 to 4, wherein the second conjugated diene-based copolymer has a Mooney viscosity (MV) at 100°C of 160 to 180. Composition. The content of the first conjugated diene-based copolymer is 10 wt% to 90 wt% with respect to the total content of the conjugated diene-based copolymer composition, and the content of the second conjugated diene-based copolymer is The conjugated diene-based copolymer composition according to any one of claims 1 to 5 , wherein the content is 10% by weight to 90% by weight. 20% to 60% by weight of aromatic vinyl monomer, 35% to 75% by weight of first conjugated diene monomer, and 1% to 10% by weight of hydroxyalkyl (meth)acrylate monomer. Emulsion-polymerizing the first monomer mixture to produce a first conjugated diene-based copolymer having a Mooney viscosity (MV) at 100° C. of 30 to 120 (S10);
A second monomer mixture containing 20 wt% to 60 wt% of α-methylstyrene monomer and 40 wt% to 80 wt% of the second conjugated diene monomer is emulsion polymerized, A step (S20) of producing a second conjugated diene-based copolymer having a Mooney viscosity (MV) of more than 120 to 200 or less;
A step of mixing the first conjugated diene-based copolymer produced in the step (S10) with the second conjugated diene-based copolymer produced in the step (S20) (S30); A method for producing a diene copolymer composition. A rubber composition comprising a raw material rubber containing the conjugated diene-based copolymer composition according to claim 1. The rubber composition according to claim 8, comprising 1 part by weight to 200 parts by weight of a silica filler with respect to 100 parts by weight of the raw rubber. The rubber composition according to claim 9 , wherein the silica-based filler is one or more selected from the group consisting of wet silica, dry silica, calcium silicate, aluminum silicate, and colloidal silica.